package container;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @Author: DengJia
 * @Date: 2021/11/30 11:24
 * @Description:
 */

public class Gather {
    public static void main(String[] args) {
        Map<String, Object> chm = new ConcurrentHashMap<>();
        System.out.println(chm.isEmpty());
        System.out.println(chm.size() == 0);
        chm.put("key", "值");
        System.out.println(chm.isEmpty());
        System.out.println(chm.size() == 0);
    }
}
